Side Sleeping Position Is Associated with Less Frequent Nighttime Numbness and Tingling

Hypothesis:Side sleeping is a possible causal factor in developing carpal tunnel syndrome (CTS). Wrist and elbow flexion during sleep may be more associated with side sleeping contributing to median nerve compression.  The purpose of this study was to determine if lateral sleeping position is associated with increased nocturnal paresthesias. A secondary aim of this study was to identify if nocturnal paraestheias and sleep positions differed throughout all age groups.

Methods:A cross-sectional study of 420 participants was performed. Participants included hand clinic patients, undergraduate and medical students, and participants of the institution’s research registry. Participants were sent an anonymous online questionnaire regarding their preferred sleeping position, frequency of nighttime numbness and tingling, and risk factors for CTS.  Incomplete questionnaires were excluded. Data analysis was performed using ordinal and binary logistic regressions, and the factors considered were: age, gender, BMI, sleep position, elbow position, wrist position, CTS diagnosis, previous carpal tunnel surgery, smoking, and thyroid disease. P < 0.05 was considered significant.

Results:420 participants responded to the survey and 396 were included in the analysis. There were 128 males and 268 females, and mean age was 38.8 ±20.5 years.  On average, 33 percent of participants experienced nighttime numbness and tingling at least 1 to 2 times a week. Nineteen percent of those under 20 years of age and 26 percent of respondents between 20 and 30 years of age experienced at least 1 to 2 episodes of nighttime numbness and tingling per week. Forty-five percent preferred to sleep on only their side, 33 percent preferred to occasionally sleep on their side, and 22 percent did not prefer to sleep on their side. CTS diagnosis and increasing BMI were significantly associated with increased frequency of nighttime numbness and tingling (p=0.001 and p=0.025 respectively). Previous carpal tunnel syndrome surgery, side only sleeping, and sleeping with the wrist neutral were significantly associated with less frequent episodes (p=0.047, p=0.003, and p=0.034 respectively).

Summary Points:

• Populations even younger than 30 years of age experience occasional to frequent episodes of nocturnal paresthesias.
• These younger individuals may offer an opportunity for interventions to prevent the development of CTS.
• Preference for sleeping on only the side was associated with fewer episodes of nighttime numbness and tingling.